Drill press



` sept. 3.o,v 1947.

J. TATE DRILL PRESS` Filed Oct. 26. 1943 2 Sheets-Sheet l Janes .We

mMfL/fms J. TATE DRILL PRESS Sept. 30, 1947.

Filed Oct. 26, 1943 2- Sheets-Sheet 2A Patented Sept. 30, 1947 UNITED STATES PATENT OFFICE 1 signments, to Rockwell Manufacturing Company, Pittsburgh, Pa., a corporation of Pennsylvania Application October 26, 1943, Serial No. 507,685

7 Claims. (Cl. 77-55) The present invention relates to drill presses and is more particularly concerned with speed reducing gearing attachments, applicable to eX- isting drill presses, forreducing the speed suilciently to permit the use of the drill press in spot facing, counter sinking, counter boring, wood drilling and other operations, to thereby increase the flexibility of drill presses already in the field and adapt them for .carrying out work which they `would normally loe incapable of handling, due to the high speed of the spindle.

While attachments of this nature have been heretofore, proposed, and they have been used to a limited extent, they-are open to the objection that the drilling' thrusts are transmitted directly from the auxiliary' spindle to the main drill press spindle, resulting in excessive wear of the parts; many `of them require modification of the drill press and are of complicated costly design; others are of such construction that they cannot be successfully used when the drill press spindle has any appreciable degree of run out; and none of them embody a completely successful method of restraining thek auxiliary housing or gear casing against rotation in response to the torque reaction set up duringA operation.

secured to the drill press quill, the locking shoulder preventing the shaft from transmitting endwise thrust to the drill press spindle, with the thrust bearings associated with the auxiliary spindle transmitting the entire drilling load to the auxiliary casing. Also, by undercutting the teeth of the gear carried by the removable shaft it is possible to successfully employ the attachment, even when the drill press spindle has a substantial degree of run out.

It is accordingly a further important object of the invention to provide a slow speed attachment for drill presses embodying a gear housing and an insertable and removable input shaft which may be removed from the housing and applied directly to the drill press spindle and the housing thereafter tted upwardly over the shaft and secured to the drill press quill, thereby providing a structure which may be readily attached to the existing gear presses, `insures trouble-free operation and precludes injury to any of the drill press parts. s

Another object is to provide a slow speed attachment which may be successfully utilized even when there is considerable run out of the main f It is the major object of this invention to pro- Y vide a-slow speed attachment of novel construction which may be applied to drill presses already in the field and which permits a high input belt speed and imparts a positive, chatter-free rotation to the output spindle, .thus eliminating the usual chatter always resulting from a slow speed spindle driven directly bya belt; which may be applied to and removed from a drill with a minimum of time and leilort; and yet is of simple, low cost, rugged construction.

IV have foundrthat by providing a slow speed housing having an auxiliary spindle journalled in combined radial and thrust bearings, and an input shaft freely insertalole into and removable from the housing and carrying a gear for driving the lspeed reducing gearing, and designing the shaft for ready attachment to the existing drill press spindle, and providing a locating shoulder on the housing operable to limit the upward movement of the slow speed housing with respect to the drill press quill sufliciently to prevent the parts of the reduction gearing from being brought into endwise thrust-transmitting relationship with theV removable shaft, an attachment is provided in which the auxiliary shaft may be removed from the attachment and applied directly to the drill press spindle land thereafter the rslow speed hous-V ingmay be tted upwardly over the shaft and spindle.

A further object is tov provide a slow speed attachment for drill presseshaving means for supporting the stop rod of therdrill press on the slow speed housing in cooperative relationship with the stop lugs of the drill press structure in specification proceeds in conjunction with the annexed drawings, and from the appended claims.

In the drawings Figure 1 is a front elevational view showing the slow speed'attachment of the invention applied to a conventional drill press;

Figure 2 is a horizontal sectional view taken substantially'on the line 2-2y of Figure 1;

Figure 3 is a vertical sectional view taken substantially on the line 3-3 of Figure l;

Figure 4 is a view of the input shaft retaining member illustrating its relationship to Figure 3, at the level it assumes when installed in the upper end of the slow speed housing; and

Figure 5 is a fragmental sectional View on an enlarged scale of the needle bearing assembly.

Withcontinued reference to the drawings, in which like referencejcharacters have been ap- 3 plied to similar parts throughout the several views, the drill press to which the invention has been applied is of well known construction and comprises a vertical supporting column II, upon which the head structure designated generally as I2, is mounted for guided vertical movement. The head is adapted to be raised andl lowered on the column by means. ofa rack and pinion (not.

`capacity. A lubricant seal 46 carried in a counter y ``bore in nut 44, and a lubricant seal 41 installed l, in a counter bore 48 of the casing, preclude escape of lubricant from Vthe bearing and also exclude certain metal particles and other extraneous material. Lubricant may be introduced into the bearing in any wel1 known manner.

rotated by a hand wheel 2l. The quill is driven in well known manner by a motor driving through stepped belt and pulley assemblies (not show n) contained in atop belt guard closure 22. A torsion spring (not` shown)` contained in a closureZ-S urges shaft lsfinsuch direction as to lift the quill, and it is adjusted in well known manner to properly counterbalance 'the Weight thereof. Y

The Aconstructionv s otfar described is a conventional drill press structure and while I have illustrated the inventionas being applied thereto, it is .to be understood thatthe'invention is not limited for use therewith, 'as `it may advantageously be employed with other designs of drill presses.

lheI attachment Aof the invention comprises a speed reducing housing or casing made up of up-v per an'dlower sections ,'25` and 26, respectively, detachably's'e'cured togetherby a cap screw 21 or theV like, and Jareadily insertable and removable input .shaft '.28 Yc'arryinga preferably integral drive gear .2e at its' 'lower end; 'rn'e teeth of gear 9v are preferably undercut, approximately 0.005 inch,v for a purpose that will presently appear.

lhave''vfound that by relating the parts in this manner, 'and journallingthe auxiliary spindle inv a combined radial and thrust bearing in the auinil'i'ary housing, th'e removable shaft may be removed Afrom fthe housing ander'igidly securedV to the` diillfplress spindle and thereafter the housing maybeista11edupwardlyfover the shaft and the end ci the quill; insuring proper installation of the attachment and that lby, so ldesigning and Drorsiftqhins the, 'parte as 'to locate the lower endV ofthe shaft out jofgendwise thrust-transmittingy relationship withanyjof ythe othergparts of the structure, a slowwpeedjattachment is provdedwhih. precludes, thetensmsson f drilling thrusts to Vthe drillpress Spindle, thereby avoid-K` ing wear of the bearings in which it is Vjournalled and possible damage to the drill press.

Referring now .mure particularly ,to` Figure 3, journalled'in ball bBlgS 3l v'and 3,2 ,inthe lower end of quill, I1 ,isajdrill press `spindle 33, having a tapered innersurjface 34,1s111'chas a Morse taper,

and. a transverse slot; 35.I input shaft 28 is tapered to snuglyV lit' boreM'SllQof the spindle and carries a `tan'g- 3`6fcooperating withr the walls of bore ,3: -to positively k`e`y. the input shaft to the spinale. Ai drift may'bejirisertedin not as to release Vshaft .2,3 Y,in Vwell known manner.

The upper end pt A cas'ingfsection ,25 is .provided with a. cylindrical recess` .V31 which fits over the lower end of quilljll, anda shoulder 38 whichl abris' tbedfof 'the esilland aeufaiely locates the casing thereon. Casing section 25 is also Mountedon a reduced portionof spindle 53,.

and pulled tightly against theinner race of bearing 45 by a nut 514 threaded onV the spindle, is a gear 55, the latter being secured against rotation with respect to the spindle by a key 56. As seen in Figure 3, the `threaded end of spindle 53 terminates substantially ilush with nut 54, spaced a. material distance below the'end of shaft 28, so as to avoid the transmission of end thrust. The lower end of inputshaft 28lis provided with a cylindrical pocket 58 into.A which the reduced piloting Vportion 59 of Aspindle 53 projects, in spaced relationship to the bottom of the pocket. Aneedle'bearing assembly made up of an outer race 6I and a plurality of needle bearings 62 journals the `neighboring shaft ends upon each Y. other. The parts are preferably so dimensioned that outer race 6I may be Vpressed into opening 58- and be 'frictionall'y retained therein, it being observed vthat the race is provided with inturned ends- 53; which retain the vneedle bearings in operative assembled positions. Shaft 28 may accordingly-be freely removed from spindle portion 59, carrying the 'assembled needle bearing unit Wlithit. A bore 6 4 'in-the lowerfend ofshaft 28 provides for introduction of lubricant into the needle-bearing assembly by splash froml the interiorfof the housing. The vneedle bearing assembly preferably has -afcomparatively large degree of radial clearancewith pilot portion 59, for instance of fr'om0.00' 2`to,0ll05 inch, to permit operation withoi'it binding, evenwhen there is an appreciable amount of run -outmof the lower end of'vspind-le. v

l'jhe speed reduction between fthe input and outputjsha'fts is preferably'eifected by a countershaft-gear 'assembly carried byv afshaft 66 snugly mounted in aligned boresA in the Acasing sections andnlo'ckedfagainstrotation'.byba yset 'screw 61 meshes with drive gear 29,` and theteeth are preferably undercut 0.005 inch, soj as to operate prop-v erly even when there Endwise displacement assembly is restrained face 16 provided in section 26, and by the upperA wall 'l1 of casing section 25. e

From the foregoing it is apparent that rotation of gearA 29 will drive gear 'l5 and rotate the countershaft assembly at a reduced speed, and that rotation of thelatt'er,` through lmeshing of gears 'l2 and 55, will rotate spindle 53 at afurther remainspindle 33.I e, i, l

' Rotation of the slow speed attachment bodily about the axis of the quill is restrained by a stop rod 19 secured in a'lug 8|r on casing section 25 by means of a nut 82.v The stop rod in the present instance is the standard drill press stop rod and has been removed lfrom the collar (not shown) with which the drill press is equipped. It is provided with flat sides 83 whichslidably coact with apair of stop lugs 84 formed on head structure l2.

duced rate of speed, inthe same direction as Thestop rod accordingly restrains bodily rocking movement of the quill'and the attachment about the quillaxis in response tothe torque reaction Y developing during operation. A pair of stop nuts 85 on the rod cooperate with the lugs to limit downward movement of the quill a.V attachment.

In Figure 4 I have shown a member 8l, preferably of wood or anyfother suitable material, having a central bore 88, which is adapted to t into recess 31 of casing section 25 and to frictionally retain shaft 28 thereinA during shipping or storage, in the manner indicated by phantom lines in Figure 4. By'tightening the nut and bolt assembly 4l, member 8l may be clamped in place in theV housing with shaft 28 Vfri'ctionally fitted into opening' `88, member` 8l maintains shaft 28 out of,

contact with the other parts of the device and the assembly formsv an effective dust closure, to prevent the entranceof dirt orA extraneous material into the housing during handling.

The novel attachment of the invention is applied to the drill press as follows. The spindle 33 of the drill press is rst checked to determine the degree of run out. If it has been abused so that it runs out in excess of 0.006 inch, it should be corrected before the unit is applied; After thev spindle has been found true or has been brought to within 0.005 inch of run out, the quill is lowered about three inches and locked in place by bolt I8. y

The stop rod collar is removed from; the quill and the'stop rod installed in lug Blof the attachment. Shaft 28 is then removedfrom wood plug 81 and securely inserted 'in spindle 33.. The attachment housing is `now applied upwardly over the end of shaft 28, it being only necessary At0 grasp spindle 53 'and rock it back'and forth slightly to mesh gears 29 and 15, the needle bearing assembly freely slipping over the upper end of pilot portion 59. When shoulder 38 strikes the end of the quill the housing is clamped in place by tightening bolt assembly 4|. Installation of the attachmentis now complete and the quill is now freed by loosening clamp bolt I8 and the quill raised and lowered a few times to make sure stop rod 'I9 is properly aligned with lugs 84 and is not rubbing or binding. Nut 82 is then tightened to lock the stop rod in place. The quill return spring contained in closure 23 is now adjusted to increase the counterbalancing action and to at least partially compensate for the increased load on the quill.

The device is now ready for operation and by installing the proper tools in spindle 53 any cled sired slow speed operation, within .the capacity of the machine, may be carried out, as for example countersinking, counterboring, wood drilling andthe like, itbeing understood that the ratio of the gearing is sochosen as to give the desired speed. I have found that a speed ratio of approximately four-to-one gives very satisfactory results when applied to the drill press illustrated. It is to be understood that a Jacobs chuck or any other suitable tool holding device may be secured to spindle 53, depending upon the service desired. k

From the foregoingv detailed disclosure it is apparent-that I have provided a novel slow speed attachment which (1) may be readily applied to and removed from existing drill presses; (2) embodies an auxiliary spindle j ournalled in a bearing capable oftaking all thrust loads set up during drilling; rk(3) embodies an insertable and removablesliait unit which may be securely applied to .able shaft and excluding dust when the attachment is not in use; (6) includes a novel stop rod assembly whichabsorbs torque reaction; and (7) is of simple, low cost, rugged construction.

The invention rn vy cie forms without departing from the spirit or essential clriaracteristics thereof. embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended 'claims ratherthanby the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

',What is claimed and desired to be secured by UnitedStates Letters Patent is:

l. In a speed changing apparatus for use with a drill press having a conventional spindle, a housing adapted to -be secured to the drill press quill, said housinghavingvan open upper end;y v,an output shaft journalled in the lower portion of said housing and terminating therebelow in means for securing a cutting tool thereto, the upper end of said output shaft terminating in a cylindrical pilot portion; a shaft rigidly secured to said spindle and freely insertable through the open upper end of said housing and having a cylindrical pilot portion at its lower end; an antifriction bearing assemblyV carried by said last Y mentioned cylindrical pilot portion for journalling the pilot portions of said shafts for relative rotation and slidingly receiving said first mentioned cylindrical pilotr portion; and gear means in said housing for transmitting power from said shaft to said output shaft.

2. In a drill press having a quill mounted for reciprocation in a head structure, and a spindle journalled in the quill,r a shaft adapted to be rigidly secured to the spindle and carrying a drive gear at its lower end; a housing adapted to be slipped upwardly over said shaft and gear and having means for securing it rigidly to said quill, an output spindle journalled in a bearing in the lower portion of said housing in axial alignment with said shaft .and terminating at its lower end in means for holding Va cutting tool, the upper be embodied in other spev The present andere endofsaid output spindle and nieuwerV emi of said shaft: being jour-nailed for4` relative rotation uponeach other by bearing 'means which isl ca:-

pable of sustaining-radial loads only, said output- 3. In a drill press, a head structure; a--quill mounted for guided reoiprocatio'n on said head structure and yterminating at Vone end in a cylindricalpoition; adrill spindle mounted-for' rota#V tion` in saidl quill and 4proj acting out oisaid one end. thereof; an auxiliary housing-secured to `the cylindrical` portion of said quill and er'iclosihf'rthe proiecting portion of said spindle; ashaft 'rigidly secured' tothe projecting portion of said spindle andicarryingla-drive gear atits free end; an out put spindle mountedfor rotation ina combined radial andV thrust bearing in` said housing with its axisrin .alignment With theiaX-is 'Ofsa-id-shaft and carrying-a. driven' gea-rdisposed adiaeent to but spaced from' said drive gear and projecting outside said. auxiliary housing vand trminatin'g'in a--d'rill holding. device; said bearing-*beingoper'able to transmit the entire drillingthrusttosai'd auxiliary housing; aA countershaft journailed in said'hou-se" ing; and. carrying gears?meshingv 'With vsai'idl drive andl driven gears; bearing means journ'alling'thev inner endI of: saidshait on thelii'inei''endof said output spindle andA being incapable of Vtransmitting-axial thrust therebetween; arod rigidly se-I` curedito'said housing and disposed parallelto'sid quill ;V and abutment ineaiifs-` on saidhead struc ture cooperating with said rodl'td preclude'rota: tioniiofsaid liousingv-and saidlquill about the axis of: the latter in response toreactive torquing forces7 set' upf` during Y dri-lling; the teeth i of said driveigearL andthe gear onI saideountershaft'-Witl'in which itis meshed being undercut, and there being'suicient radial play saidY meansjuornalling said shaft on said output spindle to permitl substantial run oui-,Voix said' shaft without causing binding ofi said teeth.'

4: A gear reducingv mechanism foruse with' a drill press having a quill Ymormtedfor reciproca; tion in` a head structure'and a spindlejournalled insai-dquill; an input shaft adapted for telescopic insertion into a'r holle'wihousingV andv for slidingA engagement with anuoutput shaft and havingmeans..for rigidlysecuri-ng-it to said spindle'andv agear atitslower end; for slidin-glyl engaging' avcountershaft lge'ar. jc'mrnalled` in saidY housing; a` hollhwl housing freely applicable tosaid quilll up`vmeans for' limiting4 upward movement thereof'4 so Y Wannsee-attesta anni, means v'for featuring' said? housing-tesina duin; an output spindleP Jour-k nalflld'ir saidvllol'ls'ing'fv and -pi'o'jeting theibelw a," diiven gear on said Voutput spindle; a counter-v sha'ft insaid -housing a gear on' said countershaft meshing withl said driven gear; a second lgear on said countershaft meshable' with said drive gear onsaid'shaftwhen said housing i-s applied to said quilljv and means Vforl precluding rotation of said housinglahdfsaidf quill about the axis oi"fthe1atterv in'erespohs tfroes'set up during opration;

5? The Lapp"ara'tus defined Vin claim 4; wherein said i'jptfspindle is jur'iall'd bearing 'means in said housing which is operable to transmit all end` thrusts developing in* said' output spindle during'- operation directly to said housing, thereby relie if'd- Shaftla'nd vspindle of all end thrust shaft;

ke. A-reduetio'rigear mechanism 4for 2,- niaohin'e tolhaving adi'lve s'pindle'joiiriialled 'in' a nonfaeaeu endently' secured to' said jdri've spindle inputfga-i; agear housingl carried by said quill; aulo tp'iit spindle carriedby.saidV housingV and having. a-pilotiigprojection extending into said tosliiiglif-re'oeive said piloting projection Where-j outpu spindlefarejounalld innen-thrust transe niittirg elation'shipl;lan output gear nonerotatabISfl associated withl said output shaft; and reduc;

connecting said input' andr output gears'.

7 The combination defined in'` claim 6i whereinl saidhousirg'is apertured for telescopio assembly` over said input gear.l op .v

JAME S TTE. REFRENCESKCITEU The renewing. refereees'arie of 'recordar theV fue" ofi-'dus'- patenti uNrrE-D' STATES murmurs Nuth-hier A Name Dateipaeaosi. Forum Dec. 3o, 191eA 1,444,343? Goodwin Feb'. e; i923 inserat? Bee T Jorien-,1924] m183211- 1 Weeks- June 25; 192e turronesJIA Nason sept. 15. 1914' lrfzsrsgseafV Hoagland; Nov.' 12; 1929' 96851181. vseuustrom e V Aug; so, 1910 ill Comprising van input shaft adapted" -1 a`` hollow' toothed end forming an" 

